1. Field of the Invention
This invention relates generally to curtain wall window frames using a structural silicone bond between the glass pane assembly and the supporting curtain wall frame, and more specifically to a small connective aluminum shape that can be bonded to a glass pane assembly in a factory and which serves as a vehicle for quickly and securely affixing multiple glass pane assemblies to curtain wall window frames that encompass the outer perimeter of a building thus forming a flush glass pane curtain wall surface.
2. Description of the Related Art
A common architectural trend has been to structurally affix glass pane assembles through the use of a silicone bond to a curtain wall support frame attached to the outer perimeter of a wide variety of styles and types of buildings. A structural silicone bonded glass curtain wall is typically made up of many panes of glass which are affixed to the outer surface of the building which in turn define the outer and visible portion of the building. Such a glass curtain wall may encompass the entire structure giving the illusion of a glass building or simply occur over a small portion of the building. Functionally, the glass curtain wall also provides the windows for the building.
Certain problems are inherent any time current methods of installing the silicone bond between the glass and supporting curtain wall frames as used in a structural silicone glazed curtain wall structure. The glass pane assemblies must somehow be securely affixed to the curtain wall frame structure on the building. They must be able to flex in response to the seismic motion of the building as well as forces generated by high winds. The current available method of installing the silicone bond between the glass and curtain wall frame supporting structure is by temporarily clamping each glass pane assembly to the curtain wall frame supporting structure on the side of a building. Once clamped, each surface of the glass pane assembly and the curtain wall frame supporting structure is then carefully cleaned before installing the silicone bond. If any dirt or oil is left on the surface to be bonded during the cleaning process the silicone bond can release under high wind loads thus causing the glass pane assembly to break or become dislodged and fall from the curtain wall frame supporting structure.
One solution that deals with the installation of the silicone bond on the building is the use of a screw on clamp that has been bonded to the glass. While avoiding problems of on-site silicon bonding, this approach makes the installation of the glass curtain complicated and time consuming. One specific complication arises due to the need to provide so many screws. The high number being necessary to resist high wind loads. Even with the large number of screws, the system has questionable structural reliability due to the configuration that is required, namely providing access to the screws.
Another previous solution is the installation of several glass pane assemblies with a silicone bond on a pre-assembled curtain wall frame structure at a frame manufacturing shop or warehouse. This is also a slow process and takes special care for the handling of this large frame (usually 5xe2x80x2xc3x9713xe2x80x2) until the silicone is cured. Obviously, the glass panes must be bonded to some type of curtain wall frame support structure. Often this bonding process will be conducted in the field or on the job site, thus greatly reducing the quality and accuracy of the silicone bonding process. As can be imagined, it is very difficult to control dirt and dust in these conditions. This is especially problematic when one considers that large amounts of silicone are to be used in the bonding process.
Therefore, there exists a need to provide a sound, structural silicone bonded curtain wall support system, which allows for the quick and easy securement of structural silicone bonded glass pane assemblies to the curtain wall frame supporting structure. Furthermore, there exists a need to provide such a system wherein the glass pane assemblies may be bonded with silicone to a connective aluminum shape under factory-controlled conditions.
The present invention is a connective aluminum shape which includes an inward facing integral slot or recess that prevents rotation of the connective aluminum shape when indexed with an outward facing leg on the curtain wall frame structure. The connective aluminum shape also provides alignment between the glass pane assembly and the supporting curtain wall window frame structure. The connective aluminum shape is bonded with silicone to the inner surface of a glass pane assembly along all four sides or at least along a portion of a glass pane assembly""s perimeter. Additionally, the connective aluminum shape is bonded to the glass pane assembly under uniformly controlled factory conditions thus assuring both accurate alignment and a quality bond.
The glass pane assembly with the silicone bonded connective aluminum shape is then brought to the building site. The connective aluminum shape cooperates with a curtain wall frame support structure that can be securely attached to a permanent portion of the building such as a floor edge or a beam. The connective aluminum shape is configured to extend around the entire perimeter of the curtain wall frame openings in the preferred embodiment. Extending from the curtain wall frame support structure is a leg which projects outwardly from the curtain wall frame support structure and again is provided around the entire perimeter of the curtain wall glass pane assembly opening in the preferred embodiment. The leg projecting from the curtain wall frame support structure is caused to index with the corresponding integral slot or recess provided in the connective aluminum shape. Subsequently when the glass pane assembly with this connective aluminum shape is fully indexed, a continuous snap clamp is installed at each glass pane assembly perimeter thus quickly securing the factory bonded glass pane assembly and connective aluminum shape to the curtain wall frame support structure preventing the glass pane assembly from being separated from the building It is an object of the present invention to provide a glass pane assembly that is silicone bonded to a connective aluminum shape which is installed quickly on a curtain wall window support frame attached to a building without the time consuming process of installing this critical silicone bond to the glass pane assembly on the curtain wall frame supporting structure on the building at the job site.
It is a further object of the invention to prevent rotation of the connective aluminum shape under high wind loads or other movement by the use of a slot or recess that indexes with a leg on the curtain wall frame supporting structure. This connective aluminum shape will allow all movement of the curtain wall frame support structure while still retaining the silicone bonded glass pane assembly in place. Further, the leg indexing with the integral slot in the connective aluminum shape prevents rotation.
It is yet another object of the invention to provide a quality controlled factory bonded structural silicone glazed glass curtain wall system.